1. Field of the Invention
The present invention relates to an angle adjustment apparatus for an electronic device such as a telephone set, a television set, or an electronic calculator. More particularly, the present invention relates to technology to allow an electronic device to be held selectively in a small inclination position, a large inclination position, or a wall-hung position (upright position).
2. Description of the Related Art
For example, an example of a conventional angle setting structure for an electronic device is disclosed by Japanese laid-open patent publication No. 2004-266087, which was published and distributed prior to the filing of the present application. Such a conventional angle setting structure for an electronic device will be described below.
FIGS. 1A through 2B shows a conventional telephone set 31. FIG. 1A is a side view showing the telephone set 31 in a wall-hung position, and FIG. 1B is a plan view of the telephone set 31 shown in FIG. 1A. FIG. 2A is a side view showing the telephone set 31 inclined at a small angle on a desk, and FIG. 2B is a side view showing the telephone set 31 inclined at a large angle on the desk. Each of FIGS. 1A, 2A, and 2B partially includes a cross-sectional view.
As shown in FIGS. 1A and 1B, the telephone set 31 has a frame case including an upper case 32 and a lower case 33. Both of the upper case 32 and the lower case 33 are made of plastic. The telephone set 31 also has a display unit 34 attached near an end of the lower case 33 in a direction D. The display unit 34 has an angle-adjustable display surface. The telephone set 31 includes a handset 35 disposed on the upper case 32, a number of functional buttons 36, and a plurality of dial buttons 37.
The lower case 33 has a pair of rubber members 40 and 40 provided on a bottom 33a of the lower case 33 at an end of the lower case 33 in a direction C. The rubber members 40 are located on both sides of the lower case 33 in a direction A-B.
The telephone set 31 has a pair of first protrusions 41 and 41 arranged in parallel along the direction A-B on the bottom 33a of the lower case 33. Each of the first protrusions 41 is in the form of a flat box. The first protrusions 41 are located near the end of the bottom 33a in the direction C and formed integrally with the bottom 33a of the lower case 33. Each of the first protrusions 41 has a flat bottom 41a and a projection 42 formed integrally with the flat bottom 41a. 
The telephone set 31 has a pair of second protrusions 43 and 43 arranged in parallel along the direction A-B on the bottom 33a of the lower case 33. Each of the second protrusions 43 is in the form of a flat box having the same height as the first protrusions 41. The second protrusions 43 are located near an end of the bottom 33a in the direction D and formed integrally with the bottom 33a of the lower case 33. Each of the second protrusions 43 has a flat bottom 43a and a projection 44 formed integrally with the flat bottom 43a. 
The telephone set 31 includes hanging portions (not shown), which are used when the telephone set 31 is hung on a wall. The hanging portions are integrally formed on the bottom 33a of the lower case 33 between the first protrusions 41 and 41 and between the second protrusions 43 and 43, respectively. Each of the first protrusions 41 has a groove (not shown) formed at an end portion in the direction C for supporting axes of an arm 52, which will be described later.
The lower case 33 has first projecting pieces (not shown) integrally formed on the bottom 33a between the first protrusions 41 and the second protrusions 43. The first projecting pieces have an arcuate cross-section. Further, the second protrusions 43 have second projecting pieces integrally formed on ends of the second protrusions 43 in the direction C so as to correspond to the first projecting pieces. The second projecting pieces have an arcuate cross-section. The first projecting pieces and the second projecting pieces form axis receiving portions 49 for rotatably supporting an axis 62 of a stand 60, which will be described later. As shown in FIG. 1A, the lower case 33 has a hook 50 integrally formed near an end of the bottom 33a in the direction D. The hook 50 can be elastically deformed so as to engage with an engagement end 57 of the arm 52.
The arm 52 is made of plastic. The arm 52 is substantially in the form of a rectangle elongated in a direction C-D. The arm 52 has a base end portion 52a located at an end of the arm 52 in the direction C. The arm 52 also has a pair of small axes 53 and 53 projecting in opposite directions from both ends of the base end portion 52a. The arm 52 has holes 64 and 55 formed therein. Each of the holes 54 and 55 has a rectangular shape in a plan view. When the arm 52 is brought into contact with the bottom 33a of the lower case 33, the hanging portions are inserted into the holes 54 and 55 of the arm 52.
The arm 52 has a groove 56 formed near the center in the direction C-D. The groove 56 extends in the direction A-B and has an arcuate cross-section. When the arm 52 is brought into contact with the bottom 33a of the lower case 33, an axis 62 of the stand 60, which will be described later, is received into the groove 56. The arm 52 has a free end 52b located at an end of the arm 52 in the direction D. The engagement end 57 is provided on the free end 52b. When the engagement end 57 is brought into engagement with the hook 50 of the lower case 33, the arm 52 is held in contact with the bottom 33a of the lower case 33.
The arm 52 has a pair of first engagement portions 58 and a pair of second engagement portions 59 provided between the engagement end 57 and the groove 56. The first engagement portions 58 are arranged in a width direction (direction A-B), and the second engagement portions 59 are also arranged in the width direction (direction A-B). As shown in FIGS. 2A and 2B, the first engagement portions 58 and the second engagement portions 59 have an arcuate cross-section to receive a stay 63 of the stand 60.
The small axes 53 provided on the base end portion 52a are fitted into the grooves of the first protrusions 41 so that the arm 52 can be rotated about the small axes 53 of the base end portion 52a. Thus, the arm 52 is rotatably supported by the first protrusions 41 so that the free end 52b can be brought into contact with and away from the bottom 33a of the lower case 33. When the free end 52b of the arm 52 is brought into contact with the bottom 33a of the lower case 33, as shown in FIG. 1A, the engagement end 57 engages with the hook 50 of the lower case 33 to hold the arm 52 in place.
The stand 60 has a pair of supports 61 and 61 spaced in the width direction (direction A-B), an axis 62 connecting between base end portions 61a of the supports 61, and a stay 63 connecting between free ends 61b of the supports 61. The stay 63 is in parallel to the axis 62. Thus, the stand 60 is substantially in the form of a frame. The axis 62 is rotatably supported by the axis receiving portions 49 provided on the bottom 33a of the lower case 33. The stay 63 engages selectively with the first engagement portions 58 or the second engagement portion 59. The stand 60 includes non-slip pads 64 made of rubber. The non-slip pads 64 are attached to tips of the free ends 61b of the supports 61.
In the stand 60 thus constructed, the axis 62 is rotatably supported by the axis receiving portions 49 of the lower case 33 so that the free ends 61b can be brought into contact with and away from the bottom 33a of the lower case 33. When the free ends 61b of the stand 60 are brought into contact with the bottom 33a of the lower case 33, the arm 52 is positioned inside of the stand 60 in the width direction (direction A-B).
When the telephone set 31 thus constructed is used in a state in which the telephone set 31 is hung on a wall, the free ends 61b of the stand 60 are brought into contact with the bottom 33a of the lower case 33 while the free end 52b of the arm 52 is brought into contact with the bottom 33a of the lower case 33. As shown in FIG. 1A, the engagement end 57 of the arm 52 engages with the hook 50 of the lower case 33 so that the free end 52b is held in contact with the bottom 33a of the lower case 33. Simultaneously, the stay 63 of the stand 60 is held by the arm 52. Accordingly, the free ends 61b of the stand 60 are also held in contact with the bottom 33a of the lower case 33. Thus, the arm 52 and the stand 60 are folded and held on the lower case 33.
In this state, the stand 60 and the arm 52 are located near the lower case 33 from the bottoms 41a and 43a of the first and second protrusions 41 and 43. Accordingly, the projections 42 and 44 of the first and second protrusions 41 and 43 are brought into contact with a wall 66 as an installation surface. Specifically, the projections 42 and 44 of the first and second protrusions 41 and 43 serve as attachment portions to the wall 66. Thus, the telephone set 31 can be used in a wall-hung position without detaching the stand 60 and the arm 52 from the bottom 33a of the lower case 33. As a result, usability of the telephone set 31 can be improved. Since the stand 60 and the arm 52 remain attached to the bottom 33a of the lower case 33, the stand 60 and the arm 52 are prevented from being lost.
The use of the telephone set 31 on a desk will be described below with reference to FIGS. 2A and 2B.
First, the engagement end 57 of the arm 52 is disengaged with the hook 50 of the lower case 33. Then, as shown in FIG. 2A, the free end 52b of the arm 52 is rotated clockwise about the small axes 53. Rotation of the arm 52 allows the stay 63 held by the arm 52 to be released from the arm 52. Accordingly, the free ends 61b of the supports 61 can be rotated about the axis 62 of the stand 60. Then, the free ends 61b of the supports 61 are rotated clockwise about the axis 62 so that the stay 63 engages with the first engagement portions 58 of the arm 52. Thus, the telephone set 31 is set to have an installation angle α.
At that time, the free ends 61b of the supports 61 project from the arm 52 toward a desk 65 as an installation surface. Accordingly, the non-slip pads 64 are brought into contact with the desk 65, and the rubber members 40 are brought into contact with the desk 65. Specifically, the rubber members 40 and the non-slip pads 64 serve as attachment portions to the desk 65. In this manner, the telephone set 31 is supported by the rubber members 40 and the non-slip pads 64. Thus, the telephone set 31 is supported on the desk 65 with point contact or line contact. Accordingly, the entire stand 60 is not required to have a flat shape with accuracy. As a result, it is possible to reduce manufacturing cost of the telephone set 31.
The rubber members 40 attached to the bottom 33a of the telephone set 31 are used to support the telephone set 31. Specifically, the telephone set 31 is supported by the rubber members 40 and the non-slip pads 64 of the stand 60. Accordingly, the telephone set 31 does not require a base member having substantially the same shape as the bottom of the frame case. Therefore, the size of the telephone set 31 is prevented from being increased. Further, since the arm 52 is provided inside of the stand 60 in the width direction, the width of the arm 52 can be minimized. Additionally, the stay 63 serving as an engagement portion also serves as a reinforcement member for reinforcing the supports 61, and the stand 60 is in the form of a frame. Accordingly, it is possible to minimize a space in which the stand 60 occupies on the bottom 33a of the lower case 33. Therefore, it is possible to provide the first and second protrusions 41 and 43 and the hanging portions, which are needed when the telephone set 31 is hung on a wall, on the bottom 33a of the lower case 33. Thus, the telephone set 31 can be hung on a wall and can also be disposed on a desk.
When the installation angle α of the telephone set 31 is to be changed, the stay 63 of the stand 60 is disengaged with the first engagement portions 58 of the arm 52. Then, as shown in FIG. 2B, the stand 60 is rotated clockwise about the axis 62 so that the stay 63 engages with the second engagement portions 59. Thus, the installation angle of the telephone set 31 is changed into β. In this case, the rubber members 40 of the lower case 33 and the non-slip pads 64 of the stand 60 are also brought into contact with the desk 65. Specifically, the rubber members 40 and the non-slip pads 64 serve as attachment portions to the desk 65.
The aforementioned angle setting structure in the telephone set 31 has the following drawbacks.
(1) The arm 52, which forms an angle adjustment mechanism of the telephone set 31, has a large length and a complicated structure.
(2) The telephone set 31 becomes expensive for the reason (1).
(3) It is troublesome to attach the arm 52 and the stand 60 to the lower case 33 and detach the arm 52 and the stand 60 from the lower case 33. Accordingly, assembling and disassembling of the angle adjustment mechanism of the telephone set 31 cannot be conducted with ease.